Buggy code:
public class PartLogisticalTransporter extends PartSidedPipe implements ILogisticalTransporter { public static TransmitterIcons transporterIcons = new TransmitterIcons ( 3 , 2 ) ; public static final int SPEED = 5 ; public EnumColor color ; public int pullDelay = 0 ; public HashList < TransporterStack > transit = new HashList < TransporterStack > ( ) ; public Set < TransporterStack > needsSync = new HashSet < TransporterStack > ( ) ; @ Override public String getType ( ) { } @ Override public TransmitterType getTransmitter ( ) { } @ Override public TransmissionType getTransmissionType ( ) { } public static void registerIcons ( IIconRegister register ) { } @ Override @ SideOnly ( Side . CLIENT ) public void renderDynamic ( Vector3 pos , float f , int pass ) { } @ Override public boolean canConnect ( ForgeDirection side ) { } @ Override public byte getPossibleTransmitterConnections ( ) { } @ Override public byte getPossibleAcceptorConnections ( ) { } @ Override public IIcon getCenterIcon ( ) { } @ Override public IIcon getSideIcon ( ) { } @ Override public boolean isValidAcceptor ( TileEntity tile , ForgeDirection side ) { } @ Override public void onModeChange ( ForgeDirection side ) { } @ Override public void update ( ) { } private boolean checkSideForInsert ( TransporterStack stack ) { } private void pullItems ( ) { if ( ( pullDelay ) == 0 ) { boolean did = false ; for ( ForgeDirection side : getConnections ( PULL ) ) { TileEntity tile = Coord4D . get ( tile ( ) ) . getFromSide ( side ) . getTileEntity ( world ( ) ) ; if ( tile instanceof IInventory ) { IInventory inv = ( ( IInventory ) ( tile ) ) ; <START_BUG> InvStack stack = InventoryUtils . takeTopItem ( inv , side . getOpposite ( ) . ordinal ( ) ) ; <END_BUG> if ( ( stack != null ) && ( ( stack . getStack ( ) ) != null ) ) { ItemStack rejects = TransporterUtils . insert ( tile , this , stack . getStack ( ) , color , true , 0 ) ; if ( TransporterManager . didEmit ( stack . getStack ( ) , rejects ) ) { did = true ; stack . use ( TransporterManager . getToUse ( stack . getStack ( ) , rejects ) . stackSize ) ; } } } } if ( did ) { pullDelay = 10 ; } } else { ( pullDelay ) -- ; } } private boolean recalculate ( TransporterStack stack , Coord4D from ) { } @ Override public ItemStack insert ( Coord4D original , ItemStack itemStack , EnumColor color , boolean doEmit , int min ) { } private ItemStack insert_do ( Coord4D original , ItemStack itemStack , EnumColor color , boolean doEmit , int min , boolean force ) { } @ Override public ItemStack insertRR ( TileEntityLogisticalSorter outputter , ItemStack itemStack , EnumColor color , boolean doEmit , int min ) { } @ Override public void entityEntering ( TransporterStack stack ) { } @ Override public void onWorldJoin ( ) { } @ Override public void handlePacketData ( ByteBuf dataStream ) { } @ Override public ArrayList getNetworkedData ( ArrayList data ) { } public ArrayList getSyncPacket ( TransporterStack stack , boolean kill ) { } @ Override public void load ( NBTTagCompound nbtTags ) { } @ Override public void save ( NBTTagCompound nbtTags ) { } @ Override protected boolean onConfigure ( EntityPlayer player , int part , int side ) { } @ Override public boolean onRightClick ( EntityPlayer player , int side ) { } @ Override public EnumColor getColor ( ) { } @ Override public void setColor ( EnumColor c ) { } @ Override public TileEntity getTile ( ) { } @ Override public EnumColor getRenderColor ( ) { } @ Override public boolean canEmitTo ( TileEntity tileEntity , ForgeDirection side ) { } @ Override public boolean canReceiveFrom ( TileEntity tileEntity , ForgeDirection side ) { } @ Override public void onRemoved ( ) { } @ Override public int getCost ( ) { } }

Fix:
InvStack stack = InventoryUtils . takeTopItem ( inv , side . ordinal ( ) ) ;